# HTTP Session * Introduction * Configuration * Driver Prerequisites * Interacting With the Session * Retrieving Data * Storing Data * Flash Data * Deleting Data * Regenerating the Session ID * Session Blocking * Adding Custom Session Drivers * Implementing the Driver * Registering the Driver ## Introduction Since HTTP driven applications are stateless, sessions provide a way to store information about the user across multiple requests. That user information is typically placed in a persistent store / backend that can be accessed from subsequent requests. Laravel ships with a variety of session backends that are accessed through an expressive, unified API. Support for popular backends such as [Memcached](https://memcached.org), [Redis](https://redis.io), and databases is included. ### Configuration Your application's session configuration file is stored at `config/session.php`. Be sure to review the options available to you in this file. By default, Laravel is configured to use the `database` session driver. The session `driver` configuration option defines where session data will be stored for each request. Laravel includes a variety of drivers: * `file` \- sessions are stored in `storage/framework/sessions`. * `cookie` \- sessions are stored in secure, encrypted cookies. * `database` \- sessions are stored in a relational database. * `memcached` / `redis` \- sessions are stored in one of these fast, cache-based stores. * `dynamodb` \- sessions are stored in AWS DynamoDB. * `array` \- sessions are stored in a PHP array and will not be persisted. The array driver is primarily used during [testing](/docs/12.x/testing) and prevents the data stored in the session from being persisted. ### Driver Prerequisites #### Database When using the `database` session driver, you will need to ensure that you have a database table to contain the session data. Typically, this is included in Laravel's default `0001_01_01_000000_create_users_table.php` [database migration](/docs/12.x/migrations); however, if for any reason you do not have a `sessions` table, you may use the `make:session-table` Artisan command to generate this migration: 1php artisan make:session-table 2  3php artisan migrate php artisan make:session-table php artisan migrate #### Redis Before using Redis sessions with Laravel, you will need to either install the PhpRedis PHP extension via PECL or install the `predis/predis` package (~1.0) via Composer. For more information on configuring Redis, consult Laravel's [Redis documentation](/docs/12.x/redis#configuration). The `SESSION_CONNECTION` environment variable, or the `connection` option in the `session.php` configuration file, may be used to specify which Redis connection is used for session storage. ## Interacting With the Session ### Retrieving Data There are two primary ways of working with session data in Laravel: the global `session` helper and via a `Request` instance. First, let's look at accessing the session via a `Request` instance, which can be type-hinted on a route closure or controller method. Remember, controller method dependencies are automatically injected via the Laravel [service container](/docs/12.x/container): 1session()->get('key'); 16  17 // ... 18  19 $user = $this->users->find($id); 20  21 return view('user.profile', ['user' => $user]); 22 } 23} session()->get('key'); // ... $user = $this->users->find($id); return view('user.profile', ['user' => $user]); } } When you retrieve an item from the session, you may also pass a default value as the second argument to the `get` method. This default value will be returned if the specified key does not exist in the session. If you pass a closure as the default value to the `get` method and the requested key does not exist, the closure will be executed and its result returned: 1$value = $request->session()->get('key', 'default'); 2  3$value = $request->session()->get('key', function () { 4 return 'default'; 5}); $value = $request->session()->get('key', 'default'); $value = $request->session()->get('key', function () { return 'default'; }); #### The Global Session Helper You may also use the global `session` PHP function to retrieve and store data in the session. When the `session` helper is called with a single, string argument, it will return the value of that session key. When the helper is called with an array of key / value pairs, those values will be stored in the session: 1Route::get('/home', function () { 2 // Retrieve a piece of data from the session... 3 $value = session('key'); 4  5 // Specifying a default value... 6 $value = session('key', 'default'); 7  8 // Store a piece of data in the session... 9 session(['key' => 'value']); 10}); Route::get('/home', function () { // Retrieve a piece of data from the session... $value = session('key'); // Specifying a default value... $value = session('key', 'default'); // Store a piece of data in the session... session(['key' => 'value']); }); There is little practical difference between using the session via an HTTP request instance versus using the global `session` helper. Both methods are [testable](/docs/12.x/testing) via the `assertSessionHas` method which is available in all of your test cases. #### Retrieving All Session Data If you would like to retrieve all the data in the session, you may use the `all` method: 1$data = $request->session()->all(); $data = $request->session()->all(); #### Retrieving a Portion of the Session Data The `only` and `except` methods may be used to retrieve a subset of the session data: 1$data = $request->session()->only(['username', 'email']); 2  3$data = $request->session()->except(['username', 'email']); $data = $request->session()->only(['username', 'email']); $data = $request->session()->except(['username', 'email']); #### Determining if an Item Exists in the Session To determine if an item is present in the session, you may use the `has` method. The `has` method returns `true` if the item is present and is not `null`: 1if ($request->session()->has('users')) { 2 // ... 3} if ($request->session()->has('users')) { // ... } To determine if an item is present in the session, even if its value is `null`, you may use the `exists` method: 1if ($request->session()->exists('users')) { 2 // ... 3} if ($request->session()->exists('users')) { // ... } To determine if an item is not present in the session, you may use the `missing` method. The `missing` method returns `true` if the item is not present: 1if ($request->session()->missing('users')) { 2 // ... 3} if ($request->session()->missing('users')) { // ... } ### Storing Data To store data in the session, you will typically use the request instance's `put` method or the global `session` helper: 1// Via a request instance... 2$request->session()->put('key', 'value'); 3  4// Via the global "session" helper... 5session(['key' => 'value']); // Via a request instance... $request->session()->put('key', 'value'); // Via the global "session" helper... session(['key' => 'value']); #### Pushing to Array Session Values The `push` method may be used to push a new value onto a session value that is an array. For example, if the `user.teams` key contains an array of team names, you may push a new value onto the array like so: 1$request->session()->push('user.teams', 'developers'); $request->session()->push('user.teams', 'developers'); #### Retrieving and Deleting an Item The `pull` method will retrieve and delete an item from the session in a single statement: 1$value = $request->session()->pull('key', 'default'); $value = $request->session()->pull('key', 'default'); #### Incrementing and Decrementing Session Values If your session data contains an integer you wish to increment or decrement, you may use the `increment` and `decrement` methods: 1$request->session()->increment('count'); 2  3$request->session()->increment('count', $incrementBy = 2); 4  5$request->session()->decrement('count'); 6  7$request->session()->decrement('count', $decrementBy = 2); $request->session()->increment('count'); $request->session()->increment('count', $incrementBy = 2); $request->session()->decrement('count'); $request->session()->decrement('count', $decrementBy = 2); ### Flash Data Sometimes you may wish to store items in the session for the next request. You may do so using the `flash` method. Data stored in the session using this method will be available immediately and during the subsequent HTTP request. After the subsequent HTTP request, the flashed data will be deleted. Flash data is primarily useful for short-lived status messages: 1$request->session()->flash('status', 'Task was successful!'); $request->session()->flash('status', 'Task was successful!'); If you need to persist your flash data for several requests, you may use the `reflash` method, which will keep all of the flash data for an additional request. If you only need to keep specific flash data, you may use the `keep` method: 1$request->session()->reflash(); 2  3$request->session()->keep(['username', 'email']); $request->session()->reflash(); $request->session()->keep(['username', 'email']); To persist your flash data only for the current request, you may use the `now` method: 1$request->session()->now('status', 'Task was successful!'); $request->session()->now('status', 'Task was successful!'); ### Deleting Data The `forget` method will remove a piece of data from the session. If you would like to remove all data from the session, you may use the `flush` method: 1// Forget a single key... 2$request->session()->forget('name'); 3  4// Forget multiple keys... 5$request->session()->forget(['name', 'status']); 6  7$request->session()->flush(); // Forget a single key... $request->session()->forget('name'); // Forget multiple keys... $request->session()->forget(['name', 'status']); $request->session()->flush(); ### Regenerating the Session ID Regenerating the session ID is often done in order to prevent malicious users from exploiting a [session fixation](https://owasp.org/www- community/attacks/Session_fixation) attack on your application. Laravel automatically regenerates the session ID during authentication if you are using one of the Laravel [application starter kits](/docs/12.x/starter- kits) or [Laravel Fortify](/docs/12.x/fortify); however, if you need to manually regenerate the session ID, you may use the `regenerate` method: 1$request->session()->regenerate(); $request->session()->regenerate(); If you need to regenerate the session ID and remove all data from the session in a single statement, you may use the `invalidate` method: 1$request->session()->invalidate(); $request->session()->invalidate(); ## Session Blocking To utilize session blocking, your application must be using a cache driver that supports [atomic locks](/docs/12.x/cache#atomic-locks). Currently, those cache drivers include the `memcached`, `dynamodb`, `redis`, `mongodb` (included in the official `mongodb/laravel-mongodb` package), `database`, `file`, and `array` drivers. In addition, you may not use the `cookie` session driver. By default, Laravel allows requests using the same session to execute concurrently. So, for example, if you use a JavaScript HTTP library to make two HTTP requests to your application, they will both execute at the same time. For many applications, this is not a problem; however, session data loss can occur in a small subset of applications that make concurrent requests to two different application endpoints which both write data to the session. To mitigate this, Laravel provides functionality that allows you to limit concurrent requests for a given session. To get started, you may simply chain the `block` method onto your route definition. In this example, an incoming request to the `/profile` endpoint would acquire a session lock. While this lock is being held, any incoming requests to the `/profile` or `/order` endpoints which share the same session ID will wait for the first request to finish executing before continuing their execution: 1Route::post('/profile', function () { 2 // ... 3})->block($lockSeconds = 10, $waitSeconds = 10); 4  5Route::post('/order', function () { 6 // ... 7})->block($lockSeconds = 10, $waitSeconds = 10); Route::post('/profile', function () { // ... })->block($lockSeconds = 10, $waitSeconds = 10); Route::post('/order', function () { // ... })->block($lockSeconds = 10, $waitSeconds = 10); The `block` method accepts two optional arguments. The first argument accepted by the `block` method is the maximum number of seconds the session lock should be held for before it is released. Of course, if the request finishes executing before this time the lock will be released earlier. The second argument accepted by the `block` method is the number of seconds a request should wait while attempting to obtain a session lock. An `Illuminate\Contracts\Cache\LockTimeoutException` will be thrown if the request is unable to obtain a session lock within the given number of seconds. If neither of these arguments is passed, the lock will be obtained for a maximum of 10 seconds and requests will wait a maximum of 10 seconds while attempting to obtain a lock: 1Route::post('/profile', function () { 2 // ... 3})->block(); Route::post('/profile', function () { // ... })->block(); ## Adding Custom Session Drivers ### Implementing the Driver If none of the existing session drivers fit your application's needs, Laravel makes it possible to write your own session handler. Your custom session driver should implement PHP's built-in `SessionHandlerInterface`. This interface contains just a few simple methods. A stubbed MongoDB implementation looks like the following: 1